Switch mechanism



March '19, 1929. v VOGEL 1,705,692

SWITCH MECHANI SM Filed March 51, 1925 WITNESSES: INVENTOR W Carl Voye/ATTORNEY Patented Mar. 19, 1929.

UNITED STATES PATENT-OFFICE.

CARL VOGEL, OF EERLIN-SCHONEBERG, GERMAN Y, ASSIGNOR T WESTINGHOUSEELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

swr'ron: MECHANISM.

Application filed March 31, 1925, Serial No. 19,627, and in GermanyApril 1, 1924.

My invention relates to actuatingmechanism and particularly to mechanismfor imparting a quick or snap action to an electrical switch.

One object of my invention is to provide an actuating mechanism forswitches and apparatus requiring quick-movements in opposite directions,that is simple in construction and which is adaptable particularly tosnap switches of the tumbler type.

Another object of my invention is to provide an actuating mechanism ofthe overcenter type in which the pressure of the switch member inengagement with a contact member is maintained or actually increaseduntil the instant the switch member is separated from the contact memberwith a snap action and during the time that the actuating mechanism isapproaching the central position of its movement.

Another object of my invention is to provide an over-center actuatinmechanism for an electric switch that is adaptable for use as adouble-throw switch wherein there is no central or neutral position, butwherein the switch member is yieldingly maintained in either of twooperative positions. I

These and other objects that will be made apparent throughout thefurther description of my invention are attained by means of theactuating mechanism hereinafter described and illustrated in theaccompanying drawin wherein'the figure is an elevational View 0actuating mechanism embodying features of my invention and shown appliedto a double throw switch.

Referring to the drawing, the actuating mechanism includes a supportingbase 1 made preferably of insulating material and upon which a switchactuating earn 2 is pivotally mounted by means of a shaft 3. The camcomprises a disk having two arcuate surfaces 4 and 5 that are oppositelydisposed and c onverge to points'6 and 7 at opposite ends of the cam. Aswitch member 8, preferably consisting of a flat bronze strip which maybe flexed when pressed into engagement with contact members 9 and 10, isrigidly secured to the cam 2 and'is so positioned that it alternatelyengagesthe contact members 9 and 10 when the cam niember 2 is moved fromthe position shown to its other operative position indicated by thedot-and-dash center line A. The cam 2 is actuated by means of a pair ofoperating arms 11 and 12 that are pivotpoints 19 and 20 and the shaft16. The pur- I pose of the adjustment will hereinafter be made apparent.

The free ends of the operating arms 11 and 12 are provided with rollers21 and 22 respectively, that as indicated in the drawing normally engageopposite surfaces 4 and 5 of the cam member 2. The arms 11 and 12 arenormally biased in engagement with the cam surfaces by means of ahelical spring 23 that is pivotally connected between them. The bar 15is provided with an operating handle 24 by means of which the bar may bemoved from the position shown in the drawing to a position indicated bythe dot-anddash center line B.

When the parts are in the position shown in the drawing, the switchmember 8 is yieldingly biased to engage the contact member 9. When it isdesired to move the switch member into engagement with the switchcontact 10, the rocking bar 15 is moved to the position B which causesthe rollers 21 and 22 to be moved into engagement with the oppositesurfaces 5 and 4 respectively, of the cam member 2. As the rollers 21and 22 are moved toward the pointed ends of the cam, the pressure ofcontact between the switch member 8'and the contact member 9v isincreased because of the increase in the lengths of the lever arms ofthe forces applied to the cam by the rollers asthey approach the pointedends thereof, and by reason of the increased tension of the spring 23which is expanded as the operating arms are separated.

Because of the rollers 21 and 22 and the pointed ends of the cam member2, there can be no stable central or neutral position and consequentlyincreasing pressure is applied between theswitch member and the contactmember 9 until the rollers pass over the points of the cam, at whichtime the spring 23 will contract and cause the rollers 21 and 22 torotate the cam and thereby bring the switch member 8 into engagementwith the contact member 10. By reason of the adjustments of the pointsof attachment of the operating arms with respect to the shaft 16, thearms may be so adjusted that the rollers simultaneously engage thepoints on the cam and simultaneously act upon the opposite surface ofthe cam to cause it to change position with a snap action.

It willsbe seen from the foregoing that the movement of the cam isentirely independent of the position of the operating handle 24 afterthe rollers have moved past the central position. The hand of theoperator therefore cannot interfere with the snap action of the switch.

The movement of the switch is limited by means of stop shoulders 25 and26 on the base member 1 that are engaged by an extension 27 secured tothe cam. Movement of the free ends of the operating arms 11 and 12 isalso limited by inclined surfaces 28 and 29 on the base member which areengaged by the rollers 21 and 22 respectively.

The construction is simple and inexpensive and is applicable to avariety of switch devices wherein snap action movement of the switchmember is desired.

While I have described and illustrated several embodiments of myinvention, it will be apparent to those skilled in the art that variouschanges, modifications, substitutions, omissions and additions may bemade in the apparatus illustrated Without departing from the spirit andscope of my invention, as set forth in the appended claims.

I claim as my invention:

1. An over-center operating mechanism comprising a pivoted cam memberhaving opposite cam surfaces converging toward opposite ends thereof, arocking member, a pair of operating arms pivotally connected thereto andhaving their free ends yieldingly engaging opposite surfaces of the cammember for imparting movement thereto when the said operating membersare moved into engagement respectively with the opposite cam surfacesand means for relatively adjusting the operating arms.

2. Switch mechanism comprising a pivoted cam member having opposite camsurfaces converging toward opposite ends thereof, a stationary contactmember, a movable switch member connected to the cam member and movablethereby into and out of engagement with the contact member, a rockingmember pivoted eccentric to the cam member, a pair of operating armspivotally connected thereto and having their free ends yieldinglyengaging opposite surfaces of the cam member for imparting movementthereto when the said operating members are moved into engagementrespectively with the opposite cam surfaces.

In testimony whereof, I have hereunto subscribed my name this 12th dayof March, 1925.

CARL VOGEL.

